Association of Avoidable Hospitalizations and Continuity of Care

Continuity of care (the relationship between physician and patient that goes beyond any specific disease or episode of illness) is a key feature of primary care. Studies have suggested that increased continuity of care may lead to improved patient outcomes, as measured in fewer emergency department visits, decreased hospital admissions, better control of chronic conditions, and decreased treatment in an intensive care unit. Another measurement of continuity of care is avoidable hospitalizations, an area that has not been studied to any great extent. Researchers recently conducted a study using a longitudinal design to examine the effects of continuity of care on avoidable hospitalization and hospital admission for any condition in a healthcare system with a high level of access to care. Results of the study were reported in Archives of Internal Medicine [2010;170(18):1671-1677]. In the late 1980s, Billings and colleagues developed the classification of avoidable hospitalization to evaluate problems associated with inadequate access to primary care. The classification was based on the hypothesis that timely ambulatory care could prevent unnecessary hospitalization by preventing disease onset, controlling an acute episodic illness, or managing a chronic condition. For the current study, the researchers utilized claims data from the Longitudinal Health Insurance Database, a subset of the National Health Insurance Research Database in Taiwan. The database captured data on utilization of healthcare between January 1, 2000, and December 31, 2006. The researchers analyzed 30,830 randomly selected patients with ≥3 physician visits per year during the study period. The primary outcome measure was avoidable hospitalization and hospitalization for any condition. The researchers opted to use the Continuity of Care Index (COCI), a tool measuring the dispersion of physician visits, as the primary indicator variable. The COCI, composed of the number of different physicians seen and the number of visits to each physician, ranges between 0 and 1. The higher value corresponds to greater continuity of care. For this analysis, the COCI values were categorized into 3 equal tertiles (low [0.00-0.16], medium [0.17-0.33], and high [0.34-1.00]), according to the distribution of scores across the entire study population. The analysis categorized the patients into 3 age groups: <18 years of age, 19 to 64 years, and ≥65 years. In the 19- to 64-year age group, 36.1% of the patients were male. In 2000, in the younger age group, there were 19 mean physician visits, compared with 17 in the 19- to 64-year age group, and 27 in the older group. The proportions of patients hospitalized in 2000 were 7.8%, 9.0%, and 16.6%, respectively, among the younger, middle, and older groups. In the younger group, the COCI values tended to decrease from 2001 to 2006; the COCI values remained stable for the middle and older age groups. The rates of avoidable hospitalization decreased from 4.2% to 1.4% over time for the younger group, remained stable for the middle group, and increased from 4.6% to 8.7% for the older group. Over time, the rates for hospital admission for any condition decreased for the younger group, from 6.8% to 3.3%, remained stable for the middle age group, and increased for the older age group, from 16.9% to 24.2%. Among all 3 age groups, the likelihood of avoidable hospitalization for patients with a high or medium COCI was lower compared with patients with a low COCI. The COCI was also associated with hospital admission for any condition in all 3 age groups: the likelihood of hospital admission was lower for patients with a high or medium COCI compared with patients with a low COCI. In conclusion, the researchers summarized that “better continuity of care is associated with fewer avoidable hospitalizations and fewer hospital admissions for any condition in a healthcare system with easy access to care. Therefore, improvement of continuity of care is an appropriate path to follow in a universal coverage healthcare system.”